/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.nhncorp.neptune.changelog.pipe;

import java.io.IOException;
import java.nio.ByteBuffer;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import com.nhncorp.neptune.changelog.PipeNormallyClosed;
import com.nhncorp.neptune.changelog.pipe.Pipe.Context;

public class CloseState extends PipeState implements FaultInjectionIF {
  Log LOG = LogFactory.getLog(CloseState.class);

  public static PipeState instance() {
    return new CloseState();
  }

  public String getStateName() {
    return "Close State";
  }

  public void init(Context ctx) throws IOException {
    LOG.debug("CLOSE STATE!!!");
  }
  
  public void close(Context ctx) throws IOException {
    LOG.debug("CLOSE STATE!!!");
  }

  public boolean readFromNext(Context ctx) throws IOException {
    return closeGracefully(ctx);
  }

  private boolean closeGracefully(Context ctx) throws IOException {
    ByteBuffer buf = ByteBuffer.allocate(1);
    int numRead = 0;
    try {
      numRead = ctx.prevChannel.read(buf);
    } catch (IOException e) {
      throw new PipeNormallyClosed();
    }

    if (numRead < 0) {
      throw new PipeNormallyClosed();
    }

    return true;
  }

  public boolean readFromPrev(Context ctx) throws IOException {
    return closeGracefully(ctx);
  }
}
